In a large heavy skillet, heat 1 tablespoon of the olive oil over medium-high heat until very hot. Place the fish in the skillet and cook until browned and just opaque on the underside, 2 to 3 minutes. Carefully flip with a spatula and cook the other side until just opaque, 2 to 3 minutes more. Remove the fish to a platter or plate.

Pour the tomato-corn mixture into the hot pan (may spatter, so be careful). Let simmer for 1 to 2 minutes. Spoon the sauce over the fish and drizzle with the remaining 1 tablespoon olive oil. Serve with the lemon wedges for squeezing.